Safety handle for controllers



Nov 21 1950 H. c. KRAPF ETAL 2,530,974

SAFETY HANDLE FOR CONTROLLERS Filed Dec. 18, 1947 2 Sheets-Sheet 1 mINVENTOR5 WITNESSES Her/nan C. A rap/ a d l aul A. 1/0 Umer.

ATTOR 1950 H. c. KRAPF ET AL 2,530,974

SAFETY HANDLE FOR CONTROLLERS Filed Dec. 18, 1947 2 Sheets-Sheet 2WITNESSES: INVENTORS Her/nan 6. Arap/ and l aul L. l/a/knerz PatentedNov. 21, 1950 SAFETY HANDLE FOR. CONTROLLERS Herman C. Krapf and Paul L.Vollmer, Wilkinsburg,. 2a., assignors to Westinghouse ElectricCorporation, East Pittsburgh, Pa a corporation,

of Pennsylvania ApplioationDecember 18, 1947, Serial No. 192,380

7Claims. 1

Our invention relates generally, to controllers and, rnore,particularly,to safety handles for con- (rollers of .a type suitableforcontrollingthe operatibn, of electric locomotives. v

locomotives, cars, and other equipment nowin service,particularlyinmines, require the addition of safety devices in order tomeet the safety requirements setby, industry and government regulations.

object of our invention, generally stated, is toprovide a safety handle.for acontroller which shallbe simple and eiiicient in operation andwhich be economically manufactured and installed A morespecific objectof our inventionis to provide a safety handle which may be readilyattached to existing controllers .Another-objectof ourinvention is toprovide a controller handle which must be depressed while power isappliedto the motors controlled by. the controller.

' A further object of our invention is to so operate a contactordisposed externally of a controller that circuit interrupting duty isremoved from the controller.

Stillanother object of our invention; is to provide a controller handlewhich must be returned to the .off position and then advanced toreapply;.p0wer. to the motors after a. power failure.

Other objects of our invention will be-explained ful y, e e na e r i beappa ntq os skilled in. the art,

I In accordance with one embodiment. of our in vention, a safety handle}device ispso. constructed;-

that itmay belreadil y attached to the top of an exieting controller,The operating shaft of the. handle is: connected to the. controllershafthye;

15st; motion device which permitsthelhandleto be rotated a suitablenumber of degrees before the controller shaft is rotated; Cam SWitiCheSdiS-r,

posed within the safety, device are: so operated and connected inthecontroller circuits that power is. shutoff if; the operator releasesthehandle or moves the handle toward 1 the fofii' Rtisiti Bo r, anno inbe, ppl eduntil the, controller is returned tothe .off;1-*- position andthen advancedin the vusual manner. 7

For a better understanding of thenature and objects of our inventionreference maybe ihad to the following detailed description, taken inconjunction with the, accompanying drawings, in which:

' Figure l isa view, partially-in longitudinalsec tion and partially inelevation, of v a portion of a sntw e x od i uren e ti n B 2 is. a.VEMW, part ailypin.tmnsyersewction and na iallr ian aof: hesaretyhnd-mariachen y rhe ont ol er ,Fig- 3. a s ct o al; ew hr ushthe lostmoiq v vice for connect n the operatingshaft and; he c r ler shat- F a,4f1is1a;dia am showin nartvor the circuit. connections: for;thercontrollerr Referring, to, the drawin s; andunarticularlr to Fi the,tructu eshown; herein comprises :a p rti f a c ntr ller having,azmainsshaft m which; is rota e/J l mcunteda n a. hearing 1:. disposedinthe-top of a asinszl-l. The mainsraft ID, is. cqnnectedz to-,.acoazgigally disposed operating Sha t, 3: l-through a, lostlmo ionvdevice I14 The operating-shaft I 3 3 is 1 mtatablyxmounted in; bearinss5am; 6.:Which; are. disnosedin the top H andth bottom; l; -Lr;eSpficiY:1y-. of.-asafety: handle device, lflrwhich maybe. mountedlon top of,the co troll r: casin l2.-

The safety device I19, may beu attached to the controller b means.vofxhn adapter plate-2 lr-Which may be riveted or b lted- .to thevtoplof, the com troller casing; 12. The b,0t13Qm;,-|8i'0f; theasafetydevice I 9, maybe bolted to hthe'adapter, plate r2] by means f. boltsqllThe safety i device I 9 ishrovided with a, handle 23 whichisqvpivotallytmounted, inuarbracketzx which may be securedei o the.operatingshaft;l3. bysetscrfiws 25., Thehandlesz ,3;:may.be actuated navertical. plane-a wellasina horizontal plane,

as.- will Joev explained more, fully vhereinafter.

.Thelost; motion device lliwhichhconnects the. two shafts lll andi l3comprises =a sleeve 25::which 1 is secured to the shaft l3.;andc.a.collar 21:.which isasQQ tel tozthe Shaftzlfl. The; sleeveKZBEhasHa r ove sl 285cm:thereinand-the collar 2? is proyided; with alsrib ;2 9 which is. disposed in. the SlOfigZQgflSgShOWXI; in, Fig.5 3.The; slot128'ris so. ma-l chinedihatzthe: sleeve 25.10am rotate apre-deter minedezamountibeforeathe side of :the-slot AB-engages the-rib9.-

As shown in Figs. 1 and 2, two cam switches 34 'and-3'2-are-s0 mountedin-the safety device [9 that they maybe actuated by cams 33and'34; re-

spectively. The cam "is attached to a flanged collar'35 by screws 3 jandthe collar..35"is..secured' on,the shaft"l 3 vbyla pin 3]. "Therefore,the cam H rotates with the. shaft 1 3..

retr ta abl m untedtoni he.. haf l3! he-C0 ,larsi ll and. 42 areseparateti -by;aspiring til-amide a spring 44 which is mounted inside ofthe spring 43.

The initial pressure of the spring 44 is set by screws 45 which engage awasher 46 disposed on top of the spring 44. The pressure of the spring43 is increased by actuating the handle 23 in a vertical plane whichtransmits force to the collar 4| by depressing a plunger 41 to cause akey 38 which is disposed in a slot 49 to engage the collar All and lowerthe collar against the spring 43. As the collar 4| is lowered, itengages the washer 46 to increase the pressure of the spring 44.

In this manner the cam 33 is gripped between the collars 42 and 35 andis rotated by the collar 35 against the compression of a spring 5|. Asshown in Fig. 2, one end of the spring 3| is connected to the cam 33 andthe other end is adjustably connected to the housing of the safetydevice l9.

As also shown in Fig. 2, the rotation of the cam 33 is limited by a stoppin 52 which is mounted on one side of the housing of the safety device|9 and is disposed in a slot 53 in the cam 33. After the cam 33 has beenrotated to the limit of its travel permitted by the stop pin 52, itremains in this position so long as the handle 23 is depressed androtated in the same direction. When the cam 33 has reached the limit ofits travel,

the friction clutch 38 slips thereby permitting the handle to be rotatedfurther.

Assuming that the handle 23 is rotated in a clockwise direction from theoff position to apply power to the motors controlled by the controller,pressure is applied to the cam 33 in the manner hereinbefore describedby depressing the handle 23. When the handle is rotated in a clockwisedirection, the cam 33 is rotated a predetermined amount, for example 15,against the spring 5| until further rotation of the cam is stopped bythe stop pin 52. t the end of the 15 rotation of the cam 33, the contactmembers of the cam switch 3| are closed.

As explained hereinbefore, the lost motion device M which connects theoperating shaft l3 to the main shaft l9 has a predetermined amount oflost motion, for example, 15. Thus, the main controller shaft [6 is notrotated until after the end of the 15 motion is reached.

As shown in Fig, 2, a notch 5-4 is provided in the cam 36. The notch 53is so located that as the main controller shaft H is rotated into thefirst operating position of the controller, the contact members of thecam switch 32 are closed.

As shown in the diagram in Fig. 4, when the cam switches 3| and 32 areboth closed, the actuating coil of a line switch 55 is energized,thereby closing the line switch and applying power to the motors (notshown) through contact members 56 of the line switch. Auxiliary contactmembers 51 on the line switch 55 are also closed at this time to bridgethe contact members of the cam switch 32.

Further rotation of the handle 23 operates the controller to shuntresistance from the motor circuit in the usual manner. When thecontroller is rotated past the first operating position, the cam switch32 is opened by the cam 34. However, the energizing circuit for theactuating coil of the line switch 55 is maintained through the auxiliarycontact members 51.

If the line switch is opened for any reason, as, for example, byoperation of an overload protective device, it cannot be reclosed untilthe controller is returned to the off position and then actuated to thefirst operating position in the regular manner to reclose the camswitches 32 and 3|. Therefore, the power cannot be reapplied to themotors without the full amount of the resistance being inserted in themotor circuit.

If the operator releases the handle 23 with the controller in anyoperating position, the pressure of the friction clutch 38 on the cam 33is released and the spring 5| rotates the cam 33 in the counterclockwisedirection 15 to open the contact members of the cam switch 3| whichopens the circuit for the actuating coil of the line switch 55, therebyopening the line switch and cutting off power from the motors.

If the handle 23 is moved from any operating position toward the offposition, the first 15 of motion opens the cam switch 3| which, in turn,causes the line switch 55 to open. The 15 of counterclockwise motionwhich opens the cam switch 3| must be completed before the controllerdrum is rotated counterclockwise because of the lost motion device l4between the controller shaft and the operating shaft |3. In this manner,the motor circuit is always opened by the line switch 55, therebypreventing the contact members of the controller from opening the motorcircuit.

In order to close the circuit for the actuating coil of the line switch55, the 15 of lost motion must first be taken up and then the controllerrotated to the first operating position to close the line switch 55 inthe manner hereinbefore expiained. This necessitates that the handle 23be returned to the off position, depressed and then rotated in themanner hereinbefore described.

From the foregoing description it will be seen that the safety handledevice functions to cause power to be shut off if the operator releasesthe handle. Power is also shut off when the handle is moved from anyoperating position toward the off position and power cannot again beapplied until the controller is rotated to the off position and notchedup in the regular manner.

Thus, the device requires that the operator keep his hand on theoperating handle while power is applied to the motor. The device socontrols the operation of a line switch that circuit interrupting dutyis removed from the controller, thereby reducing the possibility offlashover and reducing controller maintenance.

Furthermore, the device requires that the controller be returned to theoff position and notched up in the regular manner in case of a powerfailure of any kind, thereby preventing the motor from being startedunless the full amount of starting resistance is in the motor circuit.This reduces the possibility of the motor flashing and prevents theequipment from starting with sudden jerks which might throw the operatorfrom his seat.

Since numerous changes may be made in the above-described construction,and different embodiments of the invention may be made without departingfrom the spirit and scope thereof, it is intended that all mattercontained in the foregoing description or shown in the accompanyingdrawing shall be interpreted as illustrative and not in a limitingsense.

We claim as our invention:

1. In a controller, in combination, a main shaft, an operating shaftdisposed coaxially with the main shaft, a handle pivotally mounted onthe operating shaft and movable in a vertical plane and in a horizontalplane, a lost motion device for connecting the operating shaft to themain shaft, a friction clutch actuated by movement of the handle in avertical plane, a cam driven by the operating shaft through the frictionclutch, switching means actuated by said cam prior to rotation of themain shaft by the handle through the lost motion device, an additionalcam secured to the operating shaft, and additional switching meansactuated by said additional cam independently of the friction clutch.

2. In a controller, in combination, a main shaft, an operating shaftdisposed coaxially with the main shaft, a handle pivotally mounted onthe operating shaft and movable in a vertical plane and in a horizontalplane, a lost motion device for connecting the operating shaft to themain shaft, a friction clutch actuated by movement of the handle in avertical plane, a cam driven by the operating shaft through the frictionclutch, switching means actuated by said cam means prior to rotation ofthe main shaft by the handle through the lost motion device, anadditional cam secured to the operating shaft, and additional switchingmeans actuated by said additional cam after rotation of the main shaftby the handle through the lost motion device.

3. In a controller, in combination, a main shaft, an operating shaftdisposed coaxially with the main shaft, a handle pivotally mounted onthe operating shaft and movable in a vertical plane and in a horizontalplane, a lost motion device for connecting the operating shaft to themain shaft, a friction clutch actuated by movement of the handle in avertical plane, a cam rotated by the operating shaft through thefriction clutch, switching means actuated by said cam, an additional camrotated by the operating shaft independently of the friction clutch, andadditional switching means actuated by said additional cam.

4. In a controller, in combination, a main shaft, an operating shaftdisposed coaxially with the main shaft, a handle pivotally mounted onthe operating shaft and movable in a vertical plane and in a horizontalplane, a lost motion device for connecting the operating shaft to themain shaft, a friction clutch actuated by movement of the handle in avertical plane, a cam rotated by the operating shaft through thefriction clutch, switching means actuated by said cam prior to rotationof the main shaft by the operating shaft through the lost motion device,an additional cam rotated by the operating shaft independently of thefriction clutch, and additional switching means actuated by saidadditional cam.

5. In a controller, in combination, a main shaft, an operating shaftdisposed coaxially with the main shaft, a handle pivotally mounted onthe operating shaft and movable in a vertical plane and in a horizontalplane, a lost motion device for connecting the operating shaft to themain shaft, a friction clutch actuated by movement of the handle in avertical plane, a cam rotated by the operating shaft through thefriction clutch, stop means for limiting the rotation of the cam,switching means actuated by said cam, an additional cam rotated by theoperating shaft independently of the friction clutch, and additionalswitching means actuated by said additional cam.

6. In a controller, in combination, a main shaft, an operating shaftdisposed coaxially with the main shaft, a handle pivotally mounted onthe operating shaft and movable in a vertical plane and in a horizontalplane, a lost motion device for connecting the operating shaft to themain shaft, a friction clutch actuated by movement of the handle in avertical plane, a cam rotated by the operating shaft through thefriction clutch, stop means for limiting the rotation of the cam,switching means actuated by said cam, and spring means for rotating saidcam to open said switching means when the friction clutch is released,an additional cam rotated by the operating shaft independently of thefriction clutch, and additional switching means actuated by saidadditional cam.

7. In a controller, in combination, a main shaft, an operating shaftdisposed coaxially with the main shaft, a handle pivotally mounted onthe operating shaft and movable in a vertical plane and in a horizontalplane, a lost motion device for connecting the operating shaft to themain shaft, a friction clutch actuated by movement of the handle in avertical plane, a cam rotated by the operating shaft through thefriction clutch, switching means actuated by said cam, an additional camsecured to the operating shaft, and additional switching means actuatedby said additional cam independently of the friction clutch.

HERMAN C. KRAPF'. PAUL L. VOLLMER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 731,375 Liggett June 16, 19031,247,911 Walkup Nov. 27, 1917 1,497,827 Acker June 17, 1924 1,806,377Whittingham May 19, 1931 2,198,469 Woodward Apr. 23, 1940 FOREIGNPATENTS Number Country Date 538,254 Great Britain July 25, 1941

